An image sensor is a device that converts an optical image into an electrical signal. The image sensor is used in digital cameras or other types of image processing devices. The image sensor includes a plurality of pixels. Mechanical shutter mode and electronic shutter mode are largely used to control an exposure time that determines the amount of photocharges that the electrical signal is based on.
The mechanical shutter mode is a method of blocking light to pixels using a mechanical device. The electronic shutter mode is usually used in complementary metal-oxide semiconductor (CMOS) image sensors. It is a method of electrically controlling an integration time during which photocharges are generated and accumulated. The electronic shutter mode includes rolling shutter mode and global shutter mode.
The rolling shutter mode is a method of controlling an integration time to be different for each row in a pixel array. The global shutter mode is a method of controlling an integration time to be the same throughout all rows in a pixel array.
The global shutter mode has an advantage of eliminating image distortion caused by different integration times among rows. However, it also has some disadvantages including a low degree of integration, and therefore, some improvements are desired.